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I agree. House needs tightened up and I am going to be remedying that. Going with the 60k will give me a goal to shoot towards. If I have to put an extra blanket on during the coldest nights of the year in the meantime, then so be it.

I wish more homeowners thought the same way.. I'd like to hear the results if you plan on putting the system in before it gets cold this winter.. Something tells me the system will keep up just fine, even before you tighten up the house. be sure to have the ductwork looked at, this is where leaks really hurt.

It's actually 33% oversized going from 45k to 60k. And that's colder than design conditions. Contractors really have issues with trusting the load calculations. My dad is due to replace his HVAC soon, house is 2,200ft in Oklahoma. I feel better about recommending the 45k to him after seeing your post, even though the existing furnaces is 125k. A/C will be going from a 4 ton down to 2.5 ton.

We got the house to 2000 cfm50. I think the load calc called for 70. Some panning was MISSING and zoning was added, so we sized smaller than load due to airflow concerns.

Now if we don't get "undersized" warnings from the software we know we are too big. If anyone has experience with manual j not oversizing, please share the data, and buy a lottery ticket, and stay AWAY from lightening storms, and can I please ride your unicorn?

I'm trying to match range, so a furnace that ranges from 20 to 60 offers huge versatility. The 3 ton 2 stage pump provides nice crossover options based upon rates, though with gas prices so low not sure there's reason to run the pump too low except maybe to avoid cycling furnace.